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Hi
I have a related question, regarding an odd phenomenon we have just
observed.
Analyzing a compound by LCMS, either in Q1 or as MRM, we get a peak
corresponding to an oxidized metabolite (+16), which elutes at the
same time
as the parent drug peak, even when we are just looking at plasma
standards.
The peak area is about 30% of that of the parent, so it's not trivial.
We can see oxidized metabolites and resolve them from parent in
patient
samples or from in vitro metabolism.
Has anyone seen what appears to be "in-source" oxidation before?
This compound is detected as a sodium adduct, but don't know if that
makes
any difference.
Regards
Alan
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Hi Alan
You did mentioned that you are detecting the analyte as M+Na adduct,
so is this misterious peak M+ K ( difference between Na and K will be
16). The best way to check will be by adding some potassium salt(KI)
in std and then checking if this peak would increase compared to your
sodium adduct.
Hope this will help.
lakshmikant bajpai
Scientist
CV Therapeutics
Palo alto CA
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